The Shared Services core, under the direction of Dr. Patterson, with the assistance of Ms. Fox and Ms. Waters, will be responsible for administrative facilitation and maximization of the research productivity of the Program Project. It will facilitate interaction between the Institution and investigators involved and the outside National Scientific Advisory Committee. It will aid with compliance with all regulatory matters involving the use of humans and animals in the proposed research. The Shared Services Core will be responsible for cytogenetic analysis of somatic cell hybrids, parental human cells used in hybrids, new human cells (in collaboration with the Clinical and Molecular Core), and rodent (primarily mouse and CHO) cells used in the research. The core will be responsible for viable, long term storage of the large collection of cell lines used by the Program Project investigators, for periodic testing for mycoplasm contamination, for growth of cells and DNA preparation as requested by Program Project investigators and for production of new somatic cell hybrids and establishment of new primary cell lines as requested. The cytogenetic function of the core will work closely with the tissue culture component so that appropriate cytogenetic analyses will be undertaken whenever cells are thawed, or whenever large cultures, e.g. for DNA preparation or biochemical analysis, are undertaken. The Core will be responsible for computerized records of all cell lines and their cytogenetic characteristics. the Core will continue to be responsible for sending cells and other reagents to all investigators requesting them. Copies of up-to-date cytogenetic analyses and special instructions, for example regarding growth conditions, will be sent routinely. The Davisson subcontract is a new function and will be responsible for supplying Program Project investigators with T 65Dn (or other) mice for breeding purposes, Northern blots and RNA samples of fetal mice, both normal and carrying relevant chromosome 16 aneuploidies, and for tissue in situ hybridization to various mouse (fetal and adult) tissues using probes generated by Program Project investigators. Over the current granting period, this Shared Services Core has evolved into an extremely efficient unit which greatly assists the work of all the investigators, and indeed, many Down Syndrome researchers worldwide.